Proxy Mobile IP (PMIP) is widely applied on the Worldwide Interoperability for Microwave Access (WiMAX) network, 3rd Generation Partnership Project (3GPP) System Architecture Evolution (SAE) network, and network systems for interworking between the 3GPP network and the WiMAX network. Generally, as shown in FIG. 1, the basic architecture of a PMIPV6 system includes:
An Authentication, Authorization and Accounting (AAA) server, which provides access authentication and authorization for the MN to access the network. Generally, on the 3GPP SAE network, the AAA server coexists with a Home Subscriber Server (HSS) that stores the subscription information of the MN. If the AAA server is separate from the HSS, the AAA server may communicate with the HSS to obtain the subscription information of the MN.
A Mobile Node, MN and a Correspondent Node, CN, being a pair of communication nodes in a point-to-point service application, and the communication nodes are corresponding to a network device such as a terminal or a server.
A Mobile Access Gateway (MAG) and a Local Mobile Anchor (LMA) are the basic network elements in the PMIPv6 system and are generally located on the gateway of access network and the gateway of core network respectively.
The basic mechanism of the PMIPv6 system is as follows: after the MN attaches to the network where the MAG is located, the MAG completes registration on behalf of the MN, and the MAG simulates a home link to advertise a Home Network Prefix (HNP) to the MN. In this way, the MN is made to think itself always located on the home link, so that the MN does not need to support mobility management.
As shown in FIG. 2, the general process of allocating an HNP by the PMIPv6 system includes the following steps:
S101, the MN attaches to the network where the MAG is located. S102, the MAG sends a first access request for the MN to the AAA server. S103, the AAA server returns a first access response to the MAG, where the access response includes service configuration information of the MN, that is, service information (including service type and Service QoS and authorization information (key materials allocated to the MN). S104, the MAG on behalf of the MN, sends a registration message (that is, a Proxy Binding Update (PBU) message) to the LMA. S105, the LMA sends a second access request for the MN to the AAA server. S106, the AAA server returns a second access response. S105 and S106 are optional. S107, the LMA allocates an HNP to the MN according to the received PBU, creates a Binding Cache Entry (BCE) regarding the HNP and a Proxy Care-of Address (PCoA) (generally referred to as the IP address of the MAG), where the BCE includes a mapping relationship between the MN ID, the HNP, and the PCoA, and acts as a proxy of the MN to send a neighbor advertisement in which the link layer address corresponding to the HNP that is allocated to the MN is asserted to be the link layer address of the LMA. S108, the LMA returns a Proxy Binding Acknowledge (PBA) message, which carries the HNP information allocated to the MN, to the MAG S109, the MAG stores the HNP information, and sends a Router Advertisement (RA), which carries the HNP, to the MN. S110, after the MN receives the RA, the MN generates a home address according to the HNP.
In the preceding basic mechanism of PMIPv6, the HNP that the LMA allocates to the MN is exclusive. That is, the LMA allocates a unique HNP to each MN, and any two MNs do not have the same HNP. Furthermore, if multiple interfaces (IFs) of an MN are attached to the network through different access technologies and are connected to the LMA, the LMA allocates different HNPs to multiple IFs of the MN.
A shared prefix is in contrast to an exclusive prefix. An HNP is used by multiple MNs, or by multiple IFs of an MN. However, the conventional PMIPv6 and MN do not support the shared prefix.
As an intelligent MN is more capable of supporting multiple IFs (that is, each IF may be attached to the network through different access technologies), the multi-IF enabled MN has more requirements for some service applications. For example, services of the multi-IF enabled MN need to be attached to the network via multiple IFs of the MN to obtain more bandwidths, or services of the multi-IF enabled MN need to be handed over between different IFs to ensure load balancing. If the same prefix (that is, the shared prefix) is used by two or more IFs of the MN, the continuity of services/sessions in such requirements can be guaranteed.
During the implementation of the present disclosure, the inventor discovers at least the following problems in the prior art:
Because the multi-IF enabled MN has multiple IFs, the conventional system cannot determine which IFs need to be allocated with a shared prefix after being attached to the network. In addition, because an IF of the MN can have one or more prefixes, the conventional system cannot determine which prefix is shared with other IFs. Therefore, the problem about how to allocate a shared prefix to the multi-IF enabled MN should be solved as soon as possible.